On Sat, 2019-03-02 at 18:30 +0800, Yu Chen wrote: > On Fri, Mar 01, 2019 at 09:39:27AM -0800, Srinivas Pandruvada wrote: > > On Fri, 2019-03-01 at 13:43 +0100, Rafael J. Wysocki wrote: > > > Hi All, > > > > > > This is how I would fix the issue reported in BZ 200759 (see this > > > patch series > > > from Yu too: https://marc.info/?l=linux-pm&m=155137672924029&w=2) > > > . > > > > > > Patch [1/2] causes intel_pstate to update all policies if it gets > > > a > > > _PPC change > > > notification and sees a global turbo disable/enable change. > > > > > > Patch [2/2] makes it update cpuinfo.max_freq for all policies in > > > those cases. > > > > > > The patches here have not been tested yet, so testing would be > > > much > > > appreciated. > > > > > > Of course, comments are welcome too! > > > > This is the only platform, someone reported such issue. > > Can we solve this by some udev rules and offline/online cpu 1-3 on > > power source change? > > > > Sound reasonable, we can deal with this BIOS problem in user space > too. But if cpu0 could not be offline, how could cpu0's policy > be updated? I thought CPU0 is not a problem as the _PPC is sent on this and policies gets updated from the following log.
# Unplug [ 25.775643] CPU 0: _PPC is 6 - frequency limited [ 25.775660] intel_pstate: set_policy cpuinfo.max 3000000 policy->max 1700000 [ 25.775666] intel_pstate: cpu:0 max_state 17 min_policy_perf:8 max_policy_perf:17 [ 25.775670] intel_pstate: cpu:0 global_min:8 global_max:30 [ 25.775674] intel_pstate: cpu:0 max_perf_ratio:17 min_perf_ratio:8 "REDUCED FREQUENCY ABOVE AFTER UNPLUG" # Re-plug [ 36.979264] CPU 0: _PPC is 6 - frequency limited [ 36.979276] intel_pstate: policy->max > max non turbo frequency [ 36.979280] intel_pstate: set_policy cpuinfo.max 3000000 policy->max 3000000 [ 36.979283] intel_pstate: cpu:0 max_state 30 min_policy_perf:8 max_policy_perf:30 [ 36.979286] intel_pstate: cpu:0 global_min:8 global_max:30 [ 36.979289] intel_pstate: cpu:0 max_perf_ratio:30 min_perf_ratio:8 Thanks, Srinivas > > Thanks, > Yu > > > There are examples of changing governors on power source change. > > https://bbs.archlinux.org/viewtopic.php?id=207186 > > > > Here instead of changing governor just > > echo 0 > /sys/devices/system/cpu/cpu1/online > > echo 1 > /sys/devices/system/cpu/cpu1/online > > echo 0 > > > /sys/devices/system/cpu/cpu2/online > > echo 1 > > > /sys/devices/system/cpu/cpu2/online > > echo 0 > > > /sys/devices/system/cpu/cpu3/online > > echo 1 > > > /sys/devices/system/cpu/cpu3/online > > > > Thanks, > > Srinivas > > > > > > > > Thanks, > > > Rafael > > >
